Subject: Returned mail: see transcript for details
From: Mail Delivery Subsystem <[email-masked]>
To: <[email-masked]>
Date: Tue, 1 Aug 2006 10:48:14 -0700

The original message was received at Tue, 1 Aug 2006 10:48:04 -0700
from localhost [127.0.0.1]

   ----- The following addresses had permanent fatal errors -----
<[email-masked]>
    (reason: 551 not our customer)

   ----- Transcript of session follows -----
... while talking to gateway-a.comcast.net.:
<<< 450 busy - please try later
... while talking to gateway-s.comcast.net.:
>>> DATA
<<< 551 not our customer
550 5.1.1 <[email-masked]>... User unknown
<<< 503 need RCPT command [data]

Subject: Test Bounce Message
From: Sender Address <[email-masked]>
To: Sender Address <[email-masked]>
Date: Tue, 1 Aug 2006 10:45:12 -0700

Plaintext stuff here.